The Fire Force manga series features an extensive cast of characters created by Atsushi Ohkubo.
Special Fire Force Company 1 (第1特殊消防隊, Dai Ichi Tokushu Shōbōtai) is an elite group composed mostly of Holy Sol Temple members with jurisdiction in the Shinjuku District, the religious faith later revealed to have connections to the White Clad.
The Knights of the Ashen Flame (灰焔騎士団, Kaien Kishidan) are a warrior branch of the White-Clad (白頭巾, Shiro Zukin), a doomsday cult under the guidance of the Evangelist which has long infiltrated every branch of the Tokyo Empire and the Holy Sol Temple while being the cause of Infernal attacks.
The Evangelist's followers are provided with Adolla-infused Infernal Bugs that enter the host and cause them to be merged with a Doppelgänger, a being from the Adolla realm who is a reflection of their human counterpart as society sees them.
The White Clad's headquarters are located in the Nether, a forbidden area beneath the Tokyo Empire consisting of abandoned subway tunnels where the sun never shines.